New 12v charger and DC/DC Relay

Over the week since my drive to the SFEVA meeting, I've been charging the batteries one at a time with my manual charger.

On Friday I decided to invest in a new 12v battery charger. Some of the new ones have AGM settings on them that tailor the charging pattern to the AGM's needs. It sure would beat having my charger on a timer.
Saturday I went down to Sears to pick one up. It being the holidays, this was not easy. None were in the store and, of course, the sales people were less than helpful. I did finally find them in the auto services building out in the parking lot. It took me a little experimenting, but I found that if i used the 2 amp setting it would bring the voltage up to 14.6 before going into a 13.5 volt maintenance mode. This matched what Optima recommends on their web site, and seemed to work pretty well. Not having to check the charger every hour was a big relief too.

While charging the batteries I installed the relay I got to control the DC/DC converter. You don't want it running all the time as it will drain your battery pack. I thought I could hook it up to the switched side of the contactor (the side that is only hot when the car is running) but the Zilla didn't like that. I got a relay that has a 12v coil ans can switch up to 250v for less than $20 and a single gang plastic junction box to put it in. One side of the coil is ground the other side will come off the key switch.


Looks pretty good, no?